Safety edge for power-operated door



Dec. 1, 1964 T. L. URQUHART SAFETY EDGE FOR POWER-OPERATED DOOR Filed Sept. 19, 1960 3 Sheets-Sheet l 7 5""TTTF a l] 44- Li; 1: 1-

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THOR/V70 1. URQU/YflAT mmMw ' ATTOR/VfYS 1964 T. URQUHART 3,159,728

SAFETY EDGE FOR POWER-OPERATED DOOR Filed Sept. 19, 1960 3 Sheets-Sheet 2 IN VEN TOR. T/r'OP/VfO/V A. 0/? Q0144? 7' ATTOk/VEYS Dec. 1, 1964 T. L. URQUHART 3,159,728

SAFETY EDGE FOR POWER-OPERATED DOOR Filed Sept. 19, 1960 5 Sheets-Sheet 5 5 0, 1+ 3 H &- :l II H [n 9) v HI N 0 Q 0 N v I I '2 Q 3 3 l 3 :5

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United States Patent 3,159,728 SAFETY EDGE FOR POWER-OPERATED DOOR Thornton L. Urquhart, Farmington, Mich., assignor to Byrne Doors, Inc, Ferndale, Mich., a corporation of Michigan Filed Sept. 19, 19st), Ser. No. 56,760 It) (Jlahns. (Ci. ZOO-61.43)

This invention relates generally to a safety edge for power-operated doors and refers more particularly to safety means for operating a control for a door to interrupt the movement thereof.

One object of the invention is to provide safety means for operating a control to interrupt the movement of a power-operated door comprising an elongated flexible element extending along the leading edge of the door and movable transversely of its length, and means movable with the element for operating the control.

Another object of the invention is to provide safety means for operating a control to interrupt the movement of a power-operated door comprising an elongated, flexible, resilient and extensible cable extending along the leading edge of the door which is transversely yieldable under impact, and an operator carried by the element and yieldable therewith to operate the control.

Another object of the invention is to provide safety means as described above in which the operator extends from the flexible element in the direction of movement of the door and is guided for longitudinal movement to operate the control, the guide being formed to allow a limited lateral tilting movement of the operator, and means for transforming a lateral deflection of the operator into longitudinal movement thereof to operate the control.

Another object of the invention is to provide safety means as described above in which the means for transforming a lateral deflection of the operator into a longitudinal movement thereof comprises flexible ties anchored at one end to the door on opposite sides of the operator and at the other end to the operator, the ties forming a substantial angle with the operator.

Another object of the invention is to provide safety means as described above in which the operator is composed of a rod connected at one end to the flexible element and having at the other end a part for operating the control, and a sleeve slidably receiving the rod and to which the flexible ties are connected.

Another object of the invention is to provide a safety means for a power-operated door in the form of a flexible element along the leading edge of the door with improved anchor brackets at either end of the element to support the same in operative position. The brackets hold the cable in spaced relation to the leading edge of the door and are yieldable .to allow the cable to flex under impact. The brackets automatically return the flexible element into operative position.

Other objects and advantages of the invention will become apparent as the following description proceeds, especially when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a fragmentary side elevational view, partly in section, of the leading edge of a power-operated door having a safety edge constructed according to my invention.

FiG. 2 is an elevational view of a portion of the safety means shown in FIG. 1, loo-king from the left as viewed in that figure and with the rubber sheath removed.

FIG. 3 is a sectional view taken on the line 3-3 of FIG. 2.

FIG 4 is an enlarged fragmentary detail of a portion of FIG. 1, partly in section.

FIG. 5 is a fragmentary elevational view of another 3,159,728 Patented Dec. 1, 1964 portion of FIG. 1, looking from the left in that figure and with the rubber sheath removed.

FIG. 6 is a sectional view taken along the line 66 on FIG. 1.

FIG. 7 is a fragmentary elevational view of the lower edge of a vertically movable door having a modified safety edge.

FIG. 8 is a sectional view taken on the line 8-8 of FIG. 7.

Referring more particularly to the drawings, and especially to FIGS. l-6 thereof, the numeral 10 generally indicates a horizontally movable sliding door, for opening and closing an aperture of a building, and having a vertical leading edge 12. Suitable power means are provided for moving the door between open and closed positions. Also suitable braking means are provided for holding the door in fixed position when the motor is rendered inoperative and for releasing the door when the motor is started. The motor and brake means are not shown as they are conventional.

The invention relates to a novel safety edge for simultaneously shutting off the motor and applying the brake. Referring to FIG. 1, a limit switch 14 is provided mounted on the bracket 16 near the leading edge of the door. The limit switch has an operating lever 18 provided with a roller 20 at the upper end. In the position of the parts shown in FIG. 1, the lever 18 is in the position shown whereby the motor and brake are unaffected. The lever 18 of the limit switch is held in the illustrated position by internal spring mechanism which urges it to the right as viewed in FIG. 1 against a limit stop provided by the operator 22.

The operator 22 is carried and operated by an elongated, flexible, resiiient and extensible element 24 which is mounted along the leading edge of the door in spaced relation thereto. The element 24 is made up of a cable 26 which is preferably of a strong, inextensible material, one end of which is carried by the lower bracket assembly 28 more fully described hereinafter. The other end of the cable is connected to an end cable section 30 by an intermediate tension coil spring 32. The cable section 30 is connected to the upper bracket assembly 34.

The lower bracket assembly 28 is composed of an arm 36 made up of a pair of side plates 38 connected together at one end by a nut and bolt assembly 40. The shank of the bolt of the assembly 40 extends between the plates 38 and the lower end of the cable 26 extends about the shank. A pin 42 is secured to the plates of the arm 36 at the other end and has a bent end which extends through a mounting block 44. A bushing 45 lines the hole in the mounting block and a washer 48 encircles the bent end of the pin and is held thereon by a cotter pin to prevent the pin from being withdrawn. The enlarged opening in the bushing loosely receives the pin and permits a free swivel movement of the bracket arm 36. The bracket arm 36 can thus move toward and away from the door in the plane thereof and can also move transversely of the plane of the door by virtue of the swivel mounting of the pin 42. The movement of the arm 36 from side to side, that is transversely of the plane of the door, is controlled by the link chain ties 46 which are connected to the arm 36 intermediate with its ends and also to the door at laterally spaced points of the door edge as shown in FIG. 2.

The bracket 34 for the upper end of the element is composed of an arm 48 disposed in the plane of the door which is made of a pair of laterally spaced side plates 50 connected together at one end by the nut and bolt assembly 52. The shank of the bolt of assembly 52 extends between the side plates of the arm and the cable extension 30 extends about the shank. A bent pin 54 is secured to the side plates at the opposite end of the arm and projects through a hushed hole in the block 56. The hole is enlarged to loosely receive the pin and provide a swivel connection for the bracket arm 48, and a washer 53 on the bent end of the pin is retained by a cotter pin oil to prevent the arm from being withdrawn. An arm 62 made up of a pair of side plates as is pivotally connected to the arm 34 intermediate its end-s by pin 65 and the other end of the arm 62 is pivotally connected to the door by a pivot pin 68. The pins 66 and 68 extend at right angles to the plane of the door and thereby enable the bracket arm 34 to swing in the plane of the door. The pivots and 68 prevent the arm 34 from swinging laterally, that is transversely of the plane of the door.

The bracket 70 is provided to support an intermediate section of the flexible element 24 and is exactly the same as bracket assembly 34 except that on the outer end of its arm 43 a sleeve 71 is pivoted for slidably receiving the element 2.4. The parts of bracket 7t} corresponding to those of bracket 34 are identified by the same references.

The bracket assemblies 28, 34 and 76* thus support the flexible element 24 along the leading edge of the door so that the element is normally spaced beyond the leading edge as shown. The element 24- is held under tension by the spring 32 which in effect places a torque on the arms 35 and 48 of brackets 28 and 34 tending to swing them away from the door. The limit of this movement of bracket arm 36 is provided by the link ties 46 and of bracket arm i8 by arm 62. In the event that the flexible element should be deflected as by striking an object, so that it is moved toward the edge of the door, the bracket assemblies 23, 34 and '70 may yield and allow the entire element to shift toward the edge of the door. Normally if such an impact is concentrated near the center or" the element, the element will simply stretch to permit the yielding action without appreciably causing the arms of the bracket assemblies to swing in. However, if the objeot should engage the element near one end or the other, the arm of the adjacent assembly can swing towards the edge of the door. Since the arms 36 and 4% swing in such a direction as to elongate the element, the normal tension thereon will cause the arm to return immediately to the illustrated position presenting the element in spaced relation to the door edge as illustrated, as soon as the impact or force is removed. The tension in the element will also normally hold the bracket 70 in the illustrated position.

The reason for mounting the arms 48 of the bracket assemblies 34 and 70 to prevent lateral movement is to resist wind load which might otherwise operate the safety edge. The arm 36 of the lower bracket is mounted to permit lateral swinging transversely of the plane of the door so that it will be sensitive to lateral impacts such as might be caused by the foot of a person for example. The ties 46 guide the lateral swinging of the arm 36 so that it elongates the element 24-, and thus the added tension will naturally return the arm to a central position in the plane of the door.

A rubber boot or sheath 72 is provided along the leading edge of the door, to completely cover and enclose the safety edge. It might be noted that the problem of wind load acting on the safety edge is present even though the sheath is employed.

The operator 22 extends horizontally in the plane of the door and is composed of an inner member or rod 76 and an outer sleeve 78 which slidably receives the rod. The inner end of the rod has a tubular part 7% which slidably receives the flexible element, and the other end of the rod is threaded and carries the nuts 8% which are adjustable to position the limit switch actuating part 82 carried by the rod. The part 82 is apertured so that it can move freely along the threaded end of the rod.

The door edge has a plate 83 formed with an aperture 84 which is enlarged with respect to the sleeve and provides a loose swivel type guide for the outer end thereof. The door is also formed with a bracket 86 which has an elongated narrow slot 88 receiving the operator. The

l slot 38 extends horizontally at right angles to the plane of the door and closely confines the sleeve of the operator 22 to guide its lateral deflection from one side to the other of the central median plane of the door.

A pair of link ties are provided. The link ties are connected to the bracket do at opposite ends of the slot 33 and to the sleeve. A second pair of link ties 92 is also provided, being connected to the bracket 36 on opposite sides of the operator spaced 90 from the connection of the other link ties. The opposite ends of the link ties 9?- .are connected to the sleeve. The ties form a substantial angle with the operator, preferably not less than 30 nor more than The rod 76 carries an abutment in the form of a nut which is engageable with the outer end of the sleeve 73. While the rod 76 can slide axially with respect to the sleeve, the abutment 96 provides a limit for movement of the rod relative to the sleeve in one direction.

In operation, when the door is moving in a closing direction, or to the left in FIG. 1, and its leading edge engages an object such as a parked vehicle for example, the sheath is the first thing to engage the object and immediately transmits the impact to the element 24, deflecting it transversely of its length. As a rule, the deflection of the element is in a direction toward the edge of the door. If the impact should be at the location of the operator, then the deflection due to the impact is transmitted directly to the operator. However, i; the impact should be at some point spaced from the operator, then the magnitude of deflection oi the operator will of course be proportionately reduced. The element acts somewhat as a lever, pivoting about the bracket assembly at the other side of the operator from the point of impact as a fulcrum. If the direction of the impact is in the plane of the door, a longitudinal push is placed on the operator causing its part 82. to move away from the limit switch operating lever 18 releasing the same to operate the limit switch. The limit switch is then wired up in conventional fashion to break the circuit to the motor and simultaneously close the circuit to an electrically operated brake to stop the door. Since the operator moves away from the limit switch and since a substantial portion of the operator projects beyond the leading edge of the door, provision is made for considerable door overtravel after operation of the limit switch. This is important because in any heavy power-operated door, there is necessarily a degree of over travel that cannot be eliminated and which might otherwise damage the safety edge.

Sometimes the deflection of the flexible element 24- is in a direction transverse to the plane of the door. For example, the door may come into contact with an objec placed on the ground at an angle. While the upper two bracket assemblies cannot move laterally and hence prevent lateral deflection of the flexible element due to wind load, nevertheless the element itself can be deflected laterally. The lower bracket assembly 28 is of course mounted to permit lateral deflection.

The operator 22 is sensitive to lateral deflections by reason of the pair of link ties 9d. The link ties 98 as well as the ties 92 form a substantial angle with the operator. Hence if the operator is deflected to one side or the other of the plane of the door, for example if it is deflected upwardly in FIG. 6, it swings about the anchorage of the lower tie 96, thus causing the inner end 79 of the rod to swing in an are which moves sharply towards the edge of the door. This introduces an element of longitudinal movement into the operator. The operator must of course move away from the leading edge of the door, or longitudinally, in order to operate the limit switch.

It is very important to adjust the ties 9% in such a way that any lateral deflection will result in a component of longitudinal movement. The angles of the ties 96 are very important from this standpoint. Obviously, it the angle made between the operator and the ties is too small, then the are which the operator will take when laterally deflected will be such as to produce only a slight longitudinal movement, perhaps not enough to operate the limit switch. In order that the operator may be fully sensitive to these lateral deflections, a substantial angle must be formed between the ties and the operator. On the other hand, too large an angle between the operator and the ties 9th is undesirable. If too large an angle is employed, then the longitudinal movement of the sleeve is limited. The sleeve can, of course, move longitudinally until the ties pass through the slot and to the other side of the bracket whereupon they will provide an ultimate limit to the longitudinal movement of the sleeve. In some instances the ties are too large to pass through slot 88, further limiting the longitudinal movement of the operator. Too much limitation on the longitudinal movement of the sleeve will interfere with the desired overtravel allowed. Therefore the angle must not be too large. Unless the operator is capable of a substantial excess movement to take care of the overtravel of the door, the operator itself may be damaged.

The slot 88 is desirable in that it confines the deflection of the operator to a side-to-side movement. The chains 92 guide the movement of the operator from side to side so that it will not bind in the slot. Should the operator bind in the slot, it may not snap back to the illustrated position in preparation for the next emergency operation.

Referring now to FIGS. 7 and 8, a different application of my invention is shown. In this instance, the safety edge is shown as provided along the lower edge of a vertically movable door 99 and is enclosed by a rubber boot or sheath 1%. The flexible element or cable 104 is connected at one end to a connector 1&6 which projects through an opening 168 in a plate 109 on the door, and the connector has an abutment 110 at the end. Between the connector and the plate 109 is a compression coil spring 112 placing a yielding tension on the flexible element we. The connection for the other end of the flexible element is not shown and may be a simple fixed anchorage. Sufiicient flexibility and tension are provided by the coil spring 112.

The generally vertical operator is generally indicated at 124 and comprises a rod 122 which is axially slidable within a sleeve 124. A sleeve 126 is provided at the inner end of the rod which slidably receives the cable 1.94. The operator extends through an enlarged opening 13% in the door which provides a rather loose swivel guide for the operator. The outer end of the operator is threaded and a part 132 is axially slidable thereon, being clamped in the desired axially adjusted position by the nuts 134. The part 132 engages the lever 136 of i the limit switch 138 and normally holds the arm against spring tension of the limit switch mechanism in the position illustrated in FIG. 7. On the outer threaded end portion of the rod 122, a nut is provided serving as an abutment 14 engageable with the outer end of the rod for the same purpose as the similar abutment in the first embodiment. The rod is capable of lateral deflection in the slot 142 which is elongated horizontally at right angles to the plane of the door and closely confines the sleeve 124 to guide its lateral movement.

A pair of link ties 144 are also provided, one end of each tie being connected to the door at an end of the slot 142 and the opposite ends of the ties being connected to the operator. A second pair of link ties146 are also connected to the operator, their anchored ends being on diametrically opposite sides of the operator spaced 90 from the anchored ends of the other ties.

The operation of the safety edge in this embodiment of the invention is the same as in the first embodiment.

Any deflection of the element 104 transversely of its upward push on the cable will result in a corresponding longitudinal movement of the operator, and the link ties 144 assure that any lateral deflection of the operator at right angles to the plane of the door will result in a component of longitudinal movement of the operator as guided by the aperture to similarly operate the limit switch. The limit switch when thus operated is wired to stop the motor and apply the brake.

What I claim as my invention is:

1. In a power-operated door which is movable in its own plane in a forward direction towards closed position, safety means for operating a control on said power-operated door to interrupt the forward closing movement thereof, comprising an elongated, flexible, linear element extending lengthwise along the fmward edge of sm'd door, means connecting the ends of said linear element to said door, an operator comprising an elongated omrating member extending in a rearward direction from said linear element at right angles thereto, the forward end of said operating member being connected to said linear element at a point intermediate the ends of said linear element, said operating member being longitudinally movable rearwardly relative to said door in response to a rearward deflection of said linear element, said operating member having means adjacent its rear end for operating said control in response to a rearward longitudinal movement of said operating member relative to said door, and means causing a rearward longitudinal movement of said operating member relative to said door in response to a lateral deflection of said linear element and said forward end of said operating member.

2. The safety means defined in claim 1, wherein said last mentioned means includes flexible ties each connected at their forward ends to said operator and at their rear ends to said door on opposite sides of said operator.

3. The safety means defined in claim '2, wherein said operator includes an elongated tubular member slidably receiving said operating member and to which said forward ends of said ties are connected.

4. The safety means defined in claim 3, wherein means are provided on said door for guiding the lateral deflection of said operating member.

5. The safety means defined in claim 1, wherein the control on said door has a member normally engaged on its rear side by said means on said operating member, whereby rearward longitudinal movement of said operating member causes said means thereon to move away from said control member, said control member being operated in response to the aforesaid movement of said means on said operating member away therefrom.

6. In a power-operated door which is movable in its own plane in a forward direction towards closed position, safety means for operating a control on said power-operated door to interrupt the forward closing movement thereof, comprising an elongated, flexible, linear element extending lengthwise along the forward edge of said door, means connecting the ends of said linear element to said door, an operator comprising an elongated operating member extending in a rearward direction from said linear element at right angles thereto, the forward end of said operating member being connected to said linear element at a point intermediate the ends of said linear element, said operating member being longitudinally movable rearwardly relative to said door in response to a rearward deflection of said linear element, said operating member having means adjacent its rear end for operating said control in response to a rearward longitudinal movement of said operating member relative to said door, said operator also including an elongated tubular member slidably receiving said operating member, and means connected to said tubular member and to said door causing a rearward longitudinal movement of said operating member in response to a lateral deflection of said linear element and said forward end of said operating member.

7. Safety means for operating a control for a poweroperated door to interrupt the movement thereof, comprising an elongated flexible linear element extending along the leading edge of the door, anchors connecting the ends of said element to the door, one of said anchors comprising a bracket including an arm in the plane of the door having one end attached to one end of said element, said arm extending from said one end thereof at an acute angle to said elementin an outward direction toward the opposite end of said element, the opposite end of said arm having a swivel pivoted connection to the door for swinging movement in a plane parallel to the plane of the door and also laterally with respect to the plane of the door, and means limiting the inward pivotal movement of said arm and controlling the lateral swing of said arm.

8. The safety means defined in claim 7, wherein said last-mentioned means includes flexible ties each connected at one end to said arm intermediate the ends of said arm, said ties being connected at their opposite ends to the door on laterally opposite sides of said arm.

9. Safety means for operating a control for a poweroperated door to interrupt the movement thereof, comprising an elongated flexible linearelement extending along the leading edge of the door, anchors connecting the ends of said element to the door, one ofsaid anchors comprising a bracket including an arm in the plane. of the door having one end attached to one end of said element, said arm extending from said one end thereof at an acute angle to said element in an outward direction toward the opposite end of said element, the opposite end of said arm having a swivel pivoted connection to the door for swinging movement in a plane parallel to the plane of the door and also laterally with respect to the plane of the door, means limiting the inward pivotal movement of said arm and controlling the lateral swing of said arm, an operator having an elongated operating member connected at its inner end, to an intermediate portion of said element and projecting outwardly therefrom in the direction of door movement, said operating member having a part adjacent its outer end for operating said control in response to an outward longitudinal movement of said operating member relative to. the door, said operator also having an elongatedv tubular member slidably receivingsaid operating member, and means for constraining a longitudinal movement of said operating member in response to deflection of said element and said inner end of said operating member transversely of the direction of door movement including flexible ties each connected at one end to said tubular member, said ties being connected at their opposite ends to the door on opposite sides of said operator. 7

10. Safety means for operating a control for. a poweroperated door to interrupt the movement thereof, com- 55 prising an elongated flexible linear element connected at its ends to said door and extending along the leading edge thereof, an operator comprising an elongated operating member connected at its inner end to an intermediate portion of said element and projecting outwardly therefrom in the direction of door movement, said operating member having a part adjacent its outer end for operating said control in response to an outward longitudinal movement of said operating member relative to the door, said operator also including an elongated tubular member slidably receiving said operating member, said operating member having an abutment engageable with the outer end of said tubular member to limit inward movement of said operating member relative thereto, means for constraining an outward longitudinal movement of said operating member in response to deflection of said element and said inner end of said operating member transversely of the direction of door movement including flexible ties each connected at its inner end to said tubular member, said ties being connected at their outer ends to a part of said door on opposite sides of said operator, said part of the door having a slot elongated transversely of the direction of door movement and extending between the outer ends of said ties, said slot receiving said operator and guiding the deflection thereof, additional flexible ties each connected at its inner end to said tubular member, said additional ties being spaced angularly from the first mentioned ties 90 and being connected at their outer ends, to said pant of the door, an anchor connecting one end of said linear element to the door, said anchor comprising a bracket including an arm in the plane of the door having one end attached to said one end of said linear element, said arm extending from said one end thereof at an acute angle to said element in an outward direction toward the opposite end of said element, the opposite end of said arm having a swivel pivoted connection to the door for swinging movement in a plane parallel to the plane of the door and also laterally with respect to the plane of the door, and flexible ties limiting inward pivotal movement of said arm and controlling the lateral swing thereof, each of said last-mentioned ties being connected at one end to said arm intermediate the ends thereof, said last-mentioned ties being connected at their opposite ends to the door on laterally opposite sides of said arms.

Forman Jan. 23, 1934 Norman Aug. 24, 1954 Forman Dec. 13, 1932 

1. IN A POWER-OPERATED DOOR WHICH IS MOVABLE IN ITS OWN PLANE IN A FORWARD DIRECTION TOWARDS CLOSED POSITION, SAFETY MEANS FOR OPERATING A CONTROL ON SAID POWER-OPERATED DOOR TO INTERRUPT THE FORWARD CLOSING MOVEMENT THEREOF, COMPRISING AN ELONGATED, FLEXIBLE LINEAR ELEMENT EXTENDING LENGTHWISE ALONG THE FORWARD EDGE OF SAID DOOR, MEANS CONNECTING THE ENDS OF SAID LINEAR ELEMENT TO SAID DOOR, OPERATOR COMPRISING AN ELONGATED OPERATING MEMBER EXTENDING IN A REARWARD DIRECTION FROM SAID LINEAR ELEMENT AT RIGHT ANGLES THERETO, THE FORWARD END OF SAID OPERATING MEMBER BEING CONNECTED TO SAID LINEAR ELEMENT AT A POINT INTERMEDIATE THE ENDS OF SAID LINEAR ELEMENT, SAID OPERATING MEMBER BEING LONGITUDINALLY MOVABLE REARWARDLY RELATIVE TO SAID DOOR IN RESPONSE TO A REARWARD DEFLECTION OF SAID LINEAR ELEMENT, SAID OPERATING MEMBER HAVING MEANS ADJACENT ITS REAR END FOR OPERATING SAID CONTROL IN RESPONSE TO A REARWARD LONGITUDINAL MOVEMENT OF SAID OPERATING MEMBER RELATIVE TO SAID DOOR, AND MEANS CAUSING A REARWARD LONGITUDINAL MOVEMENT OF SAID OPERATING MEMBER RELATIVE TO SAID DOOR IN RESPONSE TO A LATERAL DEFLECTION OF SAID LINEAR ELEMENT AND SAID FORWARD END OF SAID OPERATING MEMBER. 